Lock guard for trailer doors

ABSTRACT

The lock guard includes an enclosure secured to one of pivoted double doors on a trailer. The enclosure projects beyond the edge of the one door and encloses a pair of hasps when the doors lie in a closed position. An access opening is provided through the bottom wall of the enclosure to facilitate locking and unlocking a padlock joining the hasps. A second opening is provided through the upper wall of the enclosure in registry with the bottom access opening. The standard locking cam rod for trailer doors extends through these openings.

United States Patent 91 Garvey et al.

[541 LOCK GUARD FOR TRAILER DOORS [761' Inventors: C. Godfrey Garvey,2918 Center Drive, Ellicott City, Md. 21043; Harry Paul McCoy, R.R. No.1, Box 340 A, Owings Mills, Md. 21117 221 Filed: Dec. 6; 1911 211 Appl.No.: 205,206

[451 May 29,1973

FOREIGN PATENTS OR APPLICATIONS 64,533 6/1946 Denmark ..292/281 678,2288/1952 Great Britain..... ...70/DIG. 56 103,308 2/1964 Norway ..70/56Primary Examiner-Albert G. Craig, Jr. AttorneyRobert E. LeBlanc, HenryShur, Leonard F. Stoll'et al.

57 ABSTRACT The lock guard includes an enclosure secured to one ofpivoted double doors on a trailer. The enclosure projects beyond theedge of the one door and encloses a pair of hasps when the doors lie ina closed position. An access opening is provided through the bottom wallof the enclosure to facilitate locking and unlocking a padlock joiningthe hasps. A second opening is provided through the upper wall of theenclosure in registry with the bottom access opening. The standardlocking cam rod for trailer doors extends through these openings.

8 Claims, 6 Drawing Figures Patented May 29, 1973 2 Sheets-Sheet 1Patented May 29, 1973 2 Sheets-Sheet 2 LOCK GUARD FOR TRAILER DOORS Thepresent invention relates to a lock guard for preventing unauthorizedremoval of a lock and particularly relates to a lock guard for use ontrailer doors for preventing unauthorized removal of equipment and thelike contained in the trailer van.

In many instances, locks, for example of the padlock type having ashackle extending through a pair of hasps, are utilized to secure doorsand the like in a closed position and thereby prevent access to theassociated containers. Such locks, however, do not effectively servetheir intendedpurpose as they are readily broken. For example, a bar maybe readily inserted within the shackle of an ordinary padlock andutilized as a lever to break or pry the shackle from the lock.

Thus, the very purpose of the lock is defeated and access is easilyobtained to the locked container or the like.

This problem of unauthorized entry has become particularly acute atconstruction sites where construction trailers are locked and leftunattended for extended periods of time. Theft of construction and otherequipment contained within the trailers by breaking the locks andopening the trailers has reached substantial proportions. The usualtrailer lock, provided in conjunction with one or more cam rods havingpins at opposite ends engageable in keepers attached 'to the trailerframe at its upper and lower sides, has not proved effective to preventunauthorized entry into the trailer.

A number of different types of guards for locks have been proposed andconstructed in the past. Particularly, US. Pat. No. 3,590,607 disclosesa guarded lock assembly comprised of a generally rectangular housingmounted on a swinginghasp. The housing is open at one end and a padlockis received within this opening. The opening provides access to thelock. An additional guard for the lock emcompasses the shackle insidethe outer enclosure. In U.S. Pat. No. 3,392,555, there is provided apadlock having a guard assembly and which padlock and guard assembly arereceived within an enclosure. However, this enclosure is open along atleast one side thereof and would not be effective toprecludeunauthorized tampering with the shackle of the lock.

The present invention provides a guard for locks which eliminates and/orminimizes the foregoing described and other problems associated withprior lock guards and provides a novel and improved lock guardparticularly useful with trailer doors and the like and having variousadvantages in construction and use as compared with such prior lockguards. Particularly, the present invention provides an enclosure havingtop, bottom, front and end walls secured along an edge of a trailer doorand enclosing a hasp secured to the trailer door. The enclosure projectslaterally beyond the edge of the trailer door. When the door lies in aclosed position, the projecting portion overlies a hasp on a fixedportion of the trailer or on another door. An opening is providedthrough the bottom wall of the enclosure. This opening provides foraccess into the enclosure for the purpose of locking and unlocking alock, the shackle of which is received through aligned openings in thehasps. While bars or other tools and the like which could be utilizedaslevers to breakthe padlock maybe received through the access opening,this opening is small and close to the padlock whereby leverage of themagnitude sufficient to break the lock cannot be obtained. A secondopening is provided through the top wall of the enclosure in verticalregistry with the bottom access opening. These aligned openings receivethe cam rod of a standard trailer door whereby the enclosure does notinterfere with the cam rod.

In another form hereof, the lock guard is applied to a roller type door.In the closed position, the guard encloses a lock applied to haspssecured to the door and vehicle frame respectively. Access to the lockwithin the enclosure is limited whereby bars, levers or the like cannotbe inserted with leverage sufficient to force the lock.

Accordingly, it is a primary object of the present invention to providea novel and improved guard for a trailer door lock.

It is another object of the present invention to provide a novel andimproved lock guard for trailer doors and the like which is readily andeasily secured to existing trailer doors.

It is still another object of the present invention to provide a noveland improved lock guard for trailer doors and the like wherein access tothe lock is limited.

It is a related object of the present invention to provide a novel andimproved lock guard for substantially entirely enclosing a lock on avehicle door wherein access to the lock issufficiently limited as toprevent forcing the lock by levers or the like.

It is a further object of the present invention to provide a novel andimproved lock guard for the locks on trailer doors and the like whereinthe guard per se is simple in construction, readily, easily andinexpensively fabricated.

These andfurther objects and advantages of the present invention willbecome more apparent upon reference to the following specification,claims and appended drawings, wherein:

FIG. 1 is a perspective view of a trailer illustrating a lock guardconstructed in accordance with the present invention and applied to thedouble doors of a trailer;

FIG. 2 is an enlarged fragmentary perspective view of the lock guardwith parts broken out and in cross sectron;

FIG. 3 is a cross-sectional view thereof taken generally about on line3-3 in FIG. 2;

FIG. 4 is an enlarged cross-sectional view thereof taken generally abouton line 4-4 in FIG. 2;

FIG. 5 is a fragmentary enlarged cross-sectional view of the carriagebolt securing the lock guard to the trailer door and taken generallyabout on line 55 in FIG. 4; and

FIG. 6 is a rear end elevational view of the lock guard of the presentinvention as applied to a roller type door.

Referring now to the drawings, particularly to FIG. 1, there isdisclosed a conventional trailer, generally indicated 10, comprised of avan 12 mounted ona set of rear wheels 14 and a pair of supports 16adjacent the front of the van. It will be appreciated that the traileris releasably attached to a cab, not shown, whereby the trailer istransportable as part of a road vehicle. The trailer 10 may be utilized,for example at a construction site, for the storage of constructiontools and the like. The trailer includes double doors l8 and 20 hingedto the opposite sides of van 12 at 22 and 24 respectively. Door 20overlaps door 18 at their juncture and is provided with conventionallocking cams 28 which cooperate with keepers mounted on the trailerframe for maintaining the doors 18 and 20 in a locked closed position.The cams 28 are operated by a handle 30 secured to a verticallyextending cam rod 32, the opposite ends of which carry the cams 28. Itwill be appreciated that handle 30 may be locked, for example by apadlock, to preclude rotation of the cam rod. However, as will beappreciated, this handle lock can be readily broken by a bar or leverwhereby unauthorized access to the trailer can be easily obtained. Theforegoing described trailer is, of course, conventional in constructionand forms no part of the present invention.

In accordance with the present invention, there is provided anadditional lock and a lock guard therefor which cooperate one with theother to prevent unauthorized entry into van l2. Particularly, the doorsl8 and are provided with hasps 34 and 36 respectively which, when thedoors are closed, receive the shackle 38 of an additional padlock,generally indicated 40. Padlock 40 may be of any conventional type ofpadlock having a key opening along the underside of its locking body 41.

While the padlock conventionally used to lock handle 30 may be readilybroken due to its external accessibility, according to the presentinvention, there is provided a lock guard, generally indicated 42, forpadlock 40. Particularly, lock guard 42 limits access to lock 40 bybars, levers or the like to the extent that leverage sufficient to forcelock 40 by application of such tools cannot be obtained. Lock guard 42,however, permits ready access to the key opening of lock 40 whereby thelock 40 can be readily removed by authorized individuals. Guard 42comprises an enclosure 44 having top and bottom walls 46 and 48respectively, end walls 50, and a front wall 52. Enclosure 44 is openalong the side thereof opposite front wall 52. For purposes which willbecome clear from the ensuing description, the top wall 46 is providedwith an opening 54. Bottom wall 48 is also provided with an opening 56in vertical alignment with the opening 54 for reasons set forthhereinafter.

Enclosure 42 is preferably secured to the door which overlaps the otherdoor, in this instance, the door 20. To effect the securement, anglebrackets 58 and 60 are secured, for example by welding or the like, tothe top wall 46 and an end wall 50, respectively. The brackets aresecured such that, when the rear edges of enclosure 44 are locatedagainst door 20, the flanges 62 and 64 of brackets 58 and 60respectively lie flush with the edges of the enclosure and against door20. Suitable openings are provided in flanges 62 and 64 to receivecarriage bolts 66 of the type having a square shank portion. The bolts66 are secured on the inside face of door 20 by lock washers 67 and nuts69. It will be appreciated from the foregoing described constructionthat enclosure 44 swings with door 20. When door 20 is closed andoverlaps the edge of door 18, an end portion of enclosure 44 alsooverlies door 18.

As best illustrated in FIG. 2, opening 54 in enclosure 44 provides arearwardly opening slot for receiving c'am rod 32. Opening 56 permitsaccess to the lock 40 within enclosure 44. This access opening issufficiently small as to preclude forcing lock 40 by insertion of bars,levers or like tools. Since opening 56 is small and close to lock 40,leverage of the magnitude sufficient to break the lock cannot beobtained. Opening 56, on the other hand, is sufficiently large such thataccess to lock 40 within the enclosure for the purposes of locking andunlocking the double doors is readily obtained. The opening 56 is alsolocated in vertical registry with padlock 40 as well as opening 54whereby cam rod 32 extends through both openings 54 and 56. That is,enclosure 42 does not interfere with the normal operation of the cam rod32.

To utilize the lock guard and additional lock of the present invention,the hasps 34 and 36 are first secured, by carriage bolts 37, to thedouble doors 18 and 20 an equal distance from the double door centerlineso that the hasps just miss one another when door 20 swings between openor closed positions. The hasps lie in lateral registry one with theother when the doors lie in a closed position. The door 20 is providedwith openings to receive the carriage bolts 66. The enclosure is thensecured to door 20 by bolts 66 with the openings 54 and 56 receiving thecam rod 32. It will be appreciated that the right hand door is theprimary opening door and that the enclosure is therefore secured to thisdoor. Should the left hand door constitute the primary door, theenclosure would be secured to the left hand door in like manner.

After the enclosure is secured to the door 20, it will be appreciatedthat the enclosure overlies both doors when the latter lie in a closedposition with the portion of the enclosure projecting laterally fromdoor 20 overlying and engaging against door 18 thereby preventing accessto within the enclosure. The shackle 38 of padlock 40 is then insertedthrough the openings in the hasps and secured in lock body portion 41.This is readily accomplished since the opening 56 is sufficiently largeas to permit manipulation of the padlock for the purposes of closing theshackle. After the padlock is secured, it is readily apparent thatcrowbars or like tools cannot be utilized on opening 54 for the purposeof forcing the lock. Particularly, leverage to break lock 40 or itsshackle by insertion of such tools through opening 56 simply cannot beobtained due to the limited access to the lock 40 through opening 56.Thus, unauthorized entry to the trailer is precluded, notwithstandingthe breaking or removal of the conventional lock utilized with handle30.

In a specific preferred embodiment of the present invention, theenclosure is 12 inches from end to end, 6 inches in depth, that is, fromthe front wall 52 to the face of the doors, and has a height of about 6inches. The enclosure is formed of one-quarter inch or 3/16 inch platesteel with all seams welded one to the other. The opening 54 is about 1inches wide and about I 7% inches deep. Opening 54 is offset about 1inch from the center of the enclosure and hence about 1 inch to one sideof the centerline of the double doors. The access opening 56 ispreferably 4 inches wide and 3 inches deep. The enclosure and hasps arerelatively located such that the key opening for padlock 40 is aboutone-half inch above the bottom wall of the enclosure. It will beappreciated that for those doors not having the cam rod and associatedlocking devices, the opening 54 through the top wall of the enclosurecan be omitted.

In the embodiment hereof illustrated in FIG. 6, a lock guard, generallyindicated 70, constructed in accordance with the present invention isapplied to a roller typetrailer door. Particularly, the trailer includesa van 72 having an overhead articulated door 74 mounted on rollerspositioned in guides along the side frame, the rollers and guides notbeing shown. It will be appreciatedthat adoor of this construction isconventional and thatthe'do'or is illustrated in the closed position.

The lock guard 70 comprises an enclosure similar to the enclosurepreviously described. Like numerals with the suffix a indicating thelock guard of this embodiment thus designate like parts. Particularly,lock guard 70 is secured to either the lower frame 76 of door 74 or tothe truck body 78 by means of the angle brackets 62a and 64a and bolts66a. Also secured to the frame 76 is a hasp 36a. A similar hasp 34a issecured to the lower frame 78 of the van. The enclosure is provided withside walls 80 and upper and lower end walls 82. The lower end wall isprovided with an opening 84 for receiving' the fixed hasp 34a mounted onframe 78 when the door is moved between open and closed positions. Theopening 84 is small and has dimensions sufficient only to providesufficient clearance for the hasp. In one of the side walls 80, there isprovided an access opening 86. It will be appreciated that, when thedoor is closed, the enclosure carried thereby encloses both hasps 34aand 36a with the former being received through the openings 84. Theshackle of the padlock is then inserted through the openings in thehasps from the side access opening 80 which again has similar dimensionsas the access'opening 56 of the previous embodiment. lt will beappreciated that the enclosure fully encompasses the hasps and liesflush against the frame 76 and 78 when the door is closed. As in theprevious embodiment, access to the padlock cannot be obtained to thedegree necessary to obtain sufficient leverage with a lever or the liketo force the padlock.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States LettersPatent is:

-1. A lock guard for use on a vehicle having a swinging door with agenerally vertically extending rod cooperable with keepers to retain thedoor in a closed position, the door including a lock cooperable with apair of locking members to lock the door in the closed positioncomprising: an enclosure having top, bottom, front and end walls, meansfor securing said enclosure to the door in position substantiallyoverlying the locking members and lock, said enclosure having an openingthrough one of said'walls providing for access to the lock within theenclosure and a second opening through another of said walls forreceiving the retaining rod, said openings being sized to limit accesswithin said enclosure such that the lock cannot be forced by insertionof levers or the like through said opening.

2. A lock guard according to claim 1 wherein said first and secondopenings are located in the respective vertically spaced walls of saidenclosure in vertical registry one with the other whereby the rod isreceivable through both of said openings.

3. A lock guard according to claim 1 wherein said securing meansincludes a pair of angle brackets welded to said enclosure.

4. A lock guard according to claim 2 wherein said second opening issmaller than said first opening.

5. A look guard according to claim 1 in combination with said vehicle,said vehicle mounting said swinging door and said rod, said lockingmembers comprising a pair of hasps respectively secured to said swingingdoor and said vehicle, said enclosure encompassing said hasps when saiddoor lies in a closed position.

6. A lock guard according to claim 5 wherein said vehicle has a secondswinging door cooperable with said first mentioned door, the other ofsaid hasps being carried by said second door, said enclosure beingcarried by said first door and projecting beyond its edge to overliesaid second door, the projecting portion of said enclosure being open onits rear side to receive said other hasp when said doors are swung to aclosed position.

7. A lock guard according to claim 1 wherein said access opening is nogreater than 12 square inches with a dimension thereof from one side ofthe opening to the other being at least 3 inches.

8. A lock guard for use on a vehicle having a door and a lock cooperablewith a pair of locking members carried by the vehicle frame and the doorrespectively for locking the door to the frame in the closed positioncomprising: an enclosure having top, bottom, front and end walls, meansfor securing said enclosure to one of the door and vehicle frame inposition substantially overlying the locking members and lock, saidenclosure having an opening through one of said walls providing foraccess to the lock within the enclosure and a second opening throughanother of said walls for receiving one of the locking members, saidopenings being sized to limit access within said enclosure such that thelock cannot be forced by insertion of levers or the like through saidopening.

1. A lock guard for use on a vehicle having a swinging door with agenerally vertically extending rod cooperable with keepers to retain thedoor in a closed position, the door including a lock cooperable with apair of locking members to lock the door in the closed positioncomprising: an enclosure having top, bottom, front and end walls, meansfor securing said enclosure to the door in position substantiallyoverlying the locking members and lock, said enclosure having an openingthrough one of said walls providing for access to the lock within theenclosure and a second opening through another of said walls forreceiving the retaining rod, said openings being sized to limit accesswithin said enclosure such that the lock cannot be forced by insertionof levers or the like through said opening.
 2. A lock guard according toclaim 1 wherein said first and second openings are located in therespective vertically spaced walls of said enclosure in verticalregistry one with the other whereby the rod is receivable through bothof said openings.
 3. A lock guard according to claim 1 wherein saidsecuring means includes a pair of angle brackets welded to saidenclosure.
 4. A lock guard according to claim 2 wherein said secondopening is smaller than said first opening.
 5. A lock guard according toclaim 1 in combination with said vehicle, said vehicle mounting saidswinging door and said rod, said locking members comprising a pair ofhasps respectively secured to said swinging door and said vehicle, saidenclosure encompassing said hasps when said door lies in a closedposition.
 6. A lock guard according to claim 5 wherein said vehicle hasa second swinging door cooperable with said first mentioned door, theother of said hasps being carried by said second door, said enclosurebeing carried by said first door and projecting beyond its edge tooverlie said second door, the projecting portion of said enclosure beingopen on its rear side to receive said other hasp when said doors areswung to a closed position.
 7. A lock guard according to claim 1 whereinsaid access opening is no greater than 12 square inches with a dimensionthereof from one side of the opening to the other being at least 3inches.
 8. A lock guard for use on a vehicle having a door and a lockcooperable with a pair of locking members carried by the vehicle frameand the door respectively for locking the door to the frame in theclosed position comprising: an enclosure having top, bottom, front andend walls, meaNs for securing said enclosure to one of the door andvehicle frame in position substantially overlying the locking membersand lock, said enclosure having an opening through one of said wallsproviding for access to the lock within the enclosure and a secondopening through another of said walls for receiving one of the lockingmembers, said openings being sized to limit access within said enclosuresuch that the lock cannot be forced by insertion of levers or the likethrough said opening.